An arrangement of an air filter and a membrane carburetor is disclosed in German patent publication 4,419,084. Here, an air filter is mounted forward of the membrane carburetor to clean the combustion air. The air filter lies essentially above the carburetor on the side of the compensation chamber thereof. The intake channel section is formed in the carburetor housing and is connected to the clean space of the air filter via an intake stub configured about at right angles. An assembly-friendly insert connection of the compensation channel is not possible because of the closeness of the clean space to the compensation chamber. For this reason, a simple sealing collar is suggested which is intended to bridge the small distance between a connecting opening in the air filter housing and the connecting opening to the compensation chamber. Such a configuration of a compensation connection, however, presents the problem of dirt entry which can lead to a plugging of the compensation channel. This can cause operational disturbances of the engine driven by the membrane carburetor.
Furthermore, the known arrangement is very large whereby problems result because of the tight spaces in the housings of portable handheld work apparatus such as motor-driven chain saws, cutoff machines, brushcutters or the like. The filter surface is small because of the minimum component space which can lead to increased flow speeds. These can operate disadvantageously on the necessary compensation of the membrane carburetor.